PHNOM PENH, CAMBODIA - Cambodian Prime Minister Hun Sen met behind closed doors with Thailand's deputy premier on Saturday as diplomatic tensions mounted over a 900-year-old temple that sits on the border between the two countries.

Thai Prime Minister Abhisit Vejjajiva sent his right-hand man, Suthep Thaugsuban, to meet Hun Sen to explain why Thailand was challenging a U.N. decision to make the Preah Vihear temple a world heritage site under the sole jurisdiction of Cambodia.

Thailand wants joint development and supervision of the Hindu temple perched on an escarpment that forms a natural border between the Southeast Asian neighbors and could one day be a lucrative tourist site.

Thailand's latest questioning of the temple's status has angered Phnom Penh, and both sides have sent more troops to the disputed area around Preah Vihear.

Reporters were kept away from Saturday's two-hour meeting on the outskirts of Phnom Penh and officials from both governments would not comment on the subject of the talks.

Hun Sen had earlier said Preah Vihear was not up for discussion and on Friday told local television that Suthep was welcome "to raise the issue of withdrawing Thai troops from the border."

In an interview with Reuters on Monday, Abhisit blamed the border tensions on UNESCO for "trying to register and manage the area when the process of demarcation hasn't been completed."

The International Court of Justice awarded the temple to Cambodia in 1962, but the ruling did not determine the ownership of 4.6 sq km of land next to the ruins, leaving considerable scope for disagreement.